Height: Difference between revisions
m Style; internalize wikipedia links; improve readability (WP:EASTER) |
Save the symbol "p" for p-adic valuation or p-limit; ratios are now consistently denoted "q". |
||
Line 15: | Line 15: | ||
# H(''q''<sup>''n''</sup>) ≥ H(''q'') for any non-negative integer ''n''. | # H(''q''<sup>''n''</sup>) ≥ H(''q'') for any non-negative integer ''n''. | ||
If we have a function F | If we have a function F which is strictly increasing on the positive reals, then F(H(''q'')) will rank elements in the same order as H(''q''). We can therefore establish the following equivalence relation: | ||
<math>\displaystyle H \left( {q} \right) \equiv F \left( {H} \left( {q} \right) \right)</math> | <math>\displaystyle H \left( {q} \right) \equiv F \left( {H} \left( {q} \right) \right)</math> | ||
A '''semi-height''' is a function which does not obey criterion #3 above, so that there is a rational number ''q'' ≠ 1 such that H(''q'') = H(1), resulting in an equivalence relation on its elements, under which #1 is modified to a finite number of equivalence classes. An example would be [[octave equivalence]], where two ratios '' | A '''semi-height''' is a function which does not obey criterion #3 above, so that there is a rational number ''q'' ≠ 1 such that H(''q'') = H(1), resulting in an equivalence relation on its elements, under which #1 is modified to a finite number of equivalence classes. An example would be [[octave equivalence]], where two ratios ''q''<sub>1</sub> and ''q''<sub>2</sub> are considered equivalent if the following is true: | ||
<math>\displaystyle 2^{-v_2 \left( { | <math>\displaystyle 2^{-v_2 \left( {q_1} \right)} q_1 = 2^{-v_2 \left( {q_2} \right)} q_2</math> | ||
where v<sub>''p''</sub>(''q'') is the [[Wikipedia: P-adic valuation|''p''-adic valuation]] of ''q''. | |||
Or equivalently, if ''n'' has any integer solutions: | Or equivalently, if ''n'' has any integer solutions: | ||
<math>\displaystyle | <math>\displaystyle q_1 = 2^n q_2</math> | ||
If the above condition is met, we may then establish the following equivalence relation: | If the above condition is met, we may then establish the following equivalence relation: | ||
<math>\displaystyle | <math>\displaystyle q_1 \equiv q_2</math> | ||
By changing the base of the exponent to a value other than 2, you can set up completely different equivalence relations. Replacing the 2 with a 3 yields tritave-equivalence, for example. | By changing the base of the exponent to a value other than 2, you can set up completely different equivalence relations. Replacing the 2 with a 3 yields tritave-equivalence, for example. | ||
Line 44: | Line 46: | ||
| [[Benedetti height]] <br> (or [[Tenney height]]) | | [[Benedetti height]] <br> (or [[Tenney height]]) | ||
| Height | | Height | ||
| <math> | | <math>nd</math> | ||
| <math>2^{\large{\|q\|_{T1}}}</math> | | <math>2^{\large{\|q\|_{T1}}}</math> | ||
| <math>\|q\|_{T1}</math> | | <math>\|q\|_{T1}</math> | ||
Line 79: | Line 81: | ||
|} | |} | ||
Where ||''q''||<sub>T1</sub> is the [[Generalized Tenney norms and Tp interval space #The Tenney Norm (T1 norm)|tenney norm]] of ''q'' in monzo form, and v<sub>''p''</sub>('' | Where ||''q''||<sub>T1</sub> is the [[Generalized Tenney norms and Tp interval space #The Tenney Norm (T1 norm)|tenney norm]] of ''q'' in monzo form, and v<sub>''p''</sub>(''q'') is the [[Wikipedia: P-adic order|''p''-adic valuation]] of ''q''. | ||
The function sopfr (''nd'') is the [https://mathworld.wolfram.com/SumofPrimeFactors.html "sum of prime factors with repetition"] of ''n''·''d''. Equivalently, this is the L<sub>1</sub> norm on monzos, but where each prime is weighted by ''p'' rather than log (''p''). This is called "Wilson's Complexity" in [[John Chalmers]]'s ''Divisions of the Tetrachord''<ref>[http://lumma.org/tuning/chalmers/DivisionsOfTheTetrachord.pdf ''Division of the Tetrachord''], page 55. John Chalmers. </ref>. | The function sopfr (''nd'') is the [https://mathworld.wolfram.com/SumofPrimeFactors.html "sum of prime factors with repetition"] of ''n''·''d''. Equivalently, this is the L<sub>1</sub> norm on monzos, but where each prime is weighted by ''p'' rather than log (''p''). This is called "Wilson's Complexity" in [[John Chalmers]]'s ''Divisions of the Tetrachord''<ref>[http://lumma.org/tuning/chalmers/DivisionsOfTheTetrachord.pdf ''Division of the Tetrachord''], page 55. John Chalmers. </ref>. |